46. On this, see St. Thomas Aquinas, Summa theologiae, 1, 79, 12.
47. Macquarrie, Three Issues in Ethics, p. 114.
48. Pope Pius XII, “Radio Message on Rightly Forming Conscience in Christian Youth,” March 23, 1952, Acta Apostolicae Sedis 44 (1952), 271.
49. Macquarrie, Three Issues in Ethics, p. 114.
50. Walter Conn, Conscience: Development and Self-Transcendence (Birmingham, AL: Religious Education Press, 1981), p. 205.
51. Ibid., p. 213.
52. See St. Thomas Aquinas, De Veritate, q. 17, a. 3.
53. St. Thomas Aquinas, Summa theologiae, 1-2, 19, 6.
54. To Live in Christ Jesus: A Pastoral Letter of the American Bishops on the Moral Life (Washington, DC: USCC, 1976), p. 10.
CHAPTER THREE
The Natural Law and Moral Life
Introduction
Vatican Council II, as we have already seen, taught that the “highest norm of human life is God’s divine law — eternal, objective, universal — whereby God orders, directs, and governs the entire universe and all the ways of the human community according to a plan conceived in wisdom and in love.” In addition, it held that “man has been made by God to participate in this law, with the result that, under the gentle disposition of divine providence, he can come to perceive ever increasingly the unchanging truth” (Dignitatis humanae, no. 3). Man’s participation in God’s divine and eternal law is precisely what the Catholic theological tradition understands by “natural law,” the law that he discovers “deep within his conscience” (Gaudium et spes, no. 16). Although they did not use the expression “natural law” to designate man’s participation in God’s divine and eternal law in these passages from Dignitatis humanae and Gaudium et spes, the Council Fathers clearly had the natural law in mind, for right after saying that “man has been made by God to participate in this law,” they explicitly referred to three texts of St. Thomas; and of these one was obviously uppermost in their mind, for in it Aquinas affirms that all human beings know the immutable truth of the eternal law at least to this extent, that they know the universal principles of the natural law.1
But what is the natural law? I propose that we begin our investigation of this topic by examining the teaching of St. Thomas on the natural law. We shall then examine the teaching of Vatican Council II, the teaching of Pope John Paul II, and the thought of some contemporary writers who seek to build on the foundations established by St. Thomas. We will consider at length the natural law position developed by Germain Grisez, John Finnis, and Joseph Boyle, taking into account Grisez’s latest views (pp. 110-111), and briefly summarize the theory set forth by Martin Rhonheimer.
NATURAL LAW IN ST. THOMAS AQUINAS
St. Thomas considered the subject of natural law formally in his Summa theologiae, but references to natural law and to such allied notions as conscience, synderesis, providence, as well as eternal and divine law are found throughout his writings, from his early “Commentary” or Scriptum on Peter Lombard’s Libri Sententiarum onward.2
In his master work, the Summa theologiae, Thomas discusses law in general, the different kinds of law (including natural law), and God’s eternal law before offering a more extensive exposition of his ideas about natural law and its relationship both to human positive law and the law of God as divinely revealed. Since natural law is “law” in a real and proper sense, it is important to begin our consideration of Thomas’s thought on natural law in the Summa theologiae by briefly summarizing his teaching on the meaning of law as such. I then propose to note succinctly his understanding of God’s eternal law. I will then turn to a consideration of his more detailed presentation of natural law.
1. The Basic Understanding of Law in the Summa Theologiae
In this work, Thomas begins by saying that law is an extrinsic principle of human acts, in distinction to virtues and vices, which are intrinsic principles of such acts. He initially describes law as “a rule or measure of acts whereby one is induced to act or is restrained from acting.” Since this is so, he says that law pertains to reason, insofar as “reason, which is the first principle of human acts, is the rule and measure of human acts.”3 Law as such is thus something that is brought into being by reason: it is an ordinatio rationis, an ordering of reason. In an enlightening response to an objection that law cannot pertain to reason because St. Paul had spoken of a “law” in his “members” (Rom 7:23), Thomas notes that law can be said to be “in” something or “pertain to” something in two ways: “In one way [law is said to be ‘in’ something] as it is in that which rules and measures. And because this is proper to reason, it follows that in this way law exists exclusively in reason.” He continues by saying that law can be said to be “in” something in a more passive, participative way, in whatever is ruled and measured by a law: “And it is in this way that law is ‘in’ all those things that are inclined toward something in virtue of some law, not essentially, but as it were in a participative sense.”4
The fact that law belongs essentially and formally to reason and is, indeed, the result of an act of intelligence is made even clearer by St. Thomas in a response that he gives to another objection. According to this objection, law cannot belong to reason since it can be neither the power of reason itself nor one of its habits or faculties, nor one of its acts. In replying to this objection, St. Thomas says that practical reason — i.e., reason as ordered to action — brings into being “universal propositions directed to action.” These universal propositions of practical reason play a role in practical thinking comparable to the role played in speculative inquiry by the universally true propositions of speculative reason relative to the conclusions that it reaches. And, Aquinas continues, “universal propositions of this kind, namely, of the practical reason as ordered to actions, have the meaning of law” (et huiusmodi propositiones universales rationis practicae ordinatae ad actiones habent rationem legis).5
From all this, it is luminously clear that in the mind of St. Thomas law as such not only belongs to reason but consists of true propositions or precepts brought into being by reason.
In subsequent articles of the Summa theologiae (1-2, 90), Thomas describes other qualities of law in the general sense. It must be ordered to the common good,6 it must come from the whole people or from someone having charge of the whole people and acting on their behalf,7 and it must be promulgated or made known.8
2. Eternal Law
Thomas taught that all creation — the cosmos and all things within it — is under the governance of God’s intelligence. Thus, the eternal law is the ratio or divine plan of the governance of all things insofar as this ratio or divine plan exists within the mind of God himself as the ruler of the universe.9 The eternal law directs the entire created universe and the activity of all created things, including the activity of human persons. Eternal law is thus the “ratio of the divine wisdom insofar as it is directive of all acts and movements.”10